The number of illegal immigrants from the mainland sneaking into the city appears to be on the rise, prompted by stronger demand in the local labour market.
In the first half of this year, 1,543 illegal mainland immigrants were arrested, compared with 1,454 in the same period last year - an increase of 6.1 per cent. This followed a 44.8 per cent leap in arrests of mainland immigrants for the whole of last year - to 3,173 from 2,191 in 2005.
'It is because Hong Kong's economy is improving and the efforts to combat illegal workers are not enough,' said legislator Wong Kwok-hing of the Federation of Trade Unions.
'Local people and mainlanders have become more geographically mobile, and some unscrupulous Hong Kong businessmen prefer to employ cheap labour to save costs.'
Mr Wong urged the Labour Department, Immigration Department and police to make more effort to clamp down on illegal workers.
The number of Vietnamese illegal immigrants grew slightly, by 2.8 per cent, from 285 in the first six months last year to 293 in the same period this year. Besides the Vietnamese, other foreign illegal immigrants arrested in the city recorded a 21-fold increase, from 24 in the first half of last year to 528 in the same period this year. They were mainly from South Asian countries including Pakistan, Nepal and Bangladesh, police said.
Police Assistant District Commander (Operations and Crime) Yu Chi-hung said: 'The demand in the labour market is one of the reasons for the increase [in mainland illegal immigrants].'
Until last year's rise, the figures had dropped steadily since 1997.
Mr Yu said the boundary fence protection system on the northern border along the Shenzhen River - which has been in use since April 2002 and involves 171 CCTV surveillance cameras and a number of thermal image detectors and fence sensors - helped deter people from trying to sneak in. Mainlanders could now come in legally with two-way permits and under the Individual Visit Scheme, he noted.
Of 1,543 mainland illegal immigrants arrested in the first half of this year, the largest number - 14.4 per cent, or 222 people - were arrested for prostitution. The number of illegal mainland prostitutes arrested has jumped from 98 in 2004 to 558 last year. Mr Yu said that was partly because the police carried out more anti-vice operations.